1. Field of the Invention
The present invention relates to an optical disc apparatus in which a tray on which an optical disc such as a CD or a DVD is placed is moved to perform operations of loading and unloading the optical disc.
2. Description of the Related Art
Conventionally, a reproduction apparatus which reads out and reproduces data recorded on an optical disc such as a CD or a DVD, and a recording apparatus which records supplied data onto such an optical disc are used. Hereinafter, such a reproduction apparatus and a recording apparatus are generally referred to as an optical disc apparatus. A tray which is disposed in an optical disc apparatus is configured so as to be movable between a loading position where an optical disc placed on the tray is to be loaded into a main unit, and a discharging position where the optical disc is to be discharged from the main unit. In the loading position, the tray is housed in the main unit, and, in the discharging position, the tray is pulled out from the main unit.
In the case where an eject switch disposed on the main unit is operated when the tray is in the loading position, the optical disc apparatus performs an unloading operation of moving the tray from the loading position to the discharging position. In the case where the eject switch disposed on the main unit is operated when the tray is in the discharging position, the optical disc apparatus performs a loading operation of moving the tray from the discharging position to the loading position. In some other optical disc apparatuses, the loading operation is performed when the tray in the discharging position is pushed toward the loading position. In a usual optical disc apparatus, the tray is moved by a torque exerted by a DC motor.
Among optical disc apparatuses, the friction between butting surfaces of a main unit and a tray is varied depending on working accuracies of the tray and the main unit. In some apparatuses, the friction is large, and, in some other apparatuses, the friction is small. In a conventional optical disc apparatus, during loading and unloading operations, a predetermined voltage is applied to a DC motor. Therefore, an optical disc apparatus in which the friction between a main unit and a tray is large has a problem in that the movement speed of the tray is so low that the loading and unloading operations require a long time period. By contrast, in an optical disc apparatus in which the friction between a main unit and a tray is small, the movement speed of the tray is so high that an optical disc placed on the tray is vibrated by a shock produced when the tray is moved or stopped, thereby causing a problem in that the optical disc rubs against the tray to be damaged.
In order to solve the problems, a technique in which a voltage to be applied to a DC motor is changed so that a tray is moved at a predetermined speed in loading and unloading operations has been proposed in JP-A-6-338119, JP-A-2000-285561, JP-A-2001-216702, and JP-A-2001-23273.
However, various factors such as the tray movement speed, the friction between butting surfaces of a main unit and the tray, and the butting state are complicatedly intertwined with one another to determine the degree of a shock which is produced during a movement of the tray. Among apparatuses, therefore, the degree of a shock which is produced during a movement of a tray is varied even at the same tray movement speed.
The conventional technique described above is that in which variation among apparatuses in the time periods of loading and unloading operations is suppressed by setting the tray movement speed in the loading and unloading operations to a predetermined one, and is not that in which variation among apparatuses in a shock produced during a movement of a tray is suppressed. In some apparatuses, therefore, a large shock remains to be produced during a movement of a tray, and an optical disc placed on the tray cannot be sufficiently prevented from rubbing against the tray to be damaged.